I have a friend in London who does financing for gold mines and she has pictures of huge cracks that go on for miles...some like 30 miles long. There was one in 2009 that formed over the course of 2 days. lh6.ggpht.com/_4Aj-mHkmt74/TUDJeo_zgOI/AAAAAAAABNc/E4qcyfqnEVM/AfricaCracks1.jpg